The present invention relates to semiconductor devices and methods of manufacturing semiconductor devices. The present invention has particular applicability to double-gate devices.
The escalating demands for high density and performance associated with ultra large scale integration semiconductor devices require design features, such as gate lengths, below 100 nanometers (nm), high reliability and increased manufacturing throughput. The reduction of design features below 100 nm challenges the limitations of conventional methodology.
For example, when the gate length of conventional planar metal oxide semiconductor field effect transistors (MOSFETs) is scaled below 100 nm, problems associated with short channel effects, such as excessive leakage between the source and drain, become increasingly difficult to overcome. In addition, mobility degradation and a number of process issues also make it difficult to scale conventional MOSFETs to include increasingly smaller device features. New device structures are therefore being explored to improve FET performance and allow further device scaling.
Double-gate MOSFETs represent new structures that have been considered as candidates for succeeding existing planar MOSFETs. In double-gate MOSFETs, two gates may be used to control short channel effects. A FinFET is a recent double-gate structure that exhibits good short channel behavior. A FinFET includes a channel formed in a vertical fin. The FinFET structure may be fabricated using layout and process techniques similar to those used for conventional planar MOSFETs.
Implementations consistent with the present invention provide methodology for forming multiple fins for use in a FinFET device. The fins, consistent with the present invention, may be formed with a small pitch.
Additional advantages and other features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the invention. The advantages and features of the invention may be realized and obtained as particularly pointed out in the appended claims.
According to the present invention, the foregoing and other advantages are achieved in part by a method of forming multiple fins in a FinFET device. The method includes depositing a dielectric layer over a silicon on insulator (SOI) wafer, where the SOI wafer includes a conductive layer on an insulating layer. The method also includes forming a resist mask over portions of the dielectric layer and etching a trench in a portion of the dielectric layer not covered by the resist mask, where the trench has two side walls. The method further includes forming spacers adjacent the two sidewalls of the trench, etching the dielectric layer to form dielectric structures located below the spacers, etching the conductive layer to form the fins and removing the spacers and the dielectric structures.
According to another aspect of the invention, a method of manufacturing a semiconductor device is provided. The method includes depositing a film over a conductive layer, where the conductive layer is used to form a plurality of fin structures. The method also includes etching at least one trench in a portion of the film, where a first trench has two side walls. The method further includes forming spacers adjacent the two sidewalls of the first trench and etching the film, where the etching terminates on the conductive layer. The method also includes etching the conductive layer to form the fin structures, forming a source region and a drain region, depositing a gate material over the fin structures and patterning and etching the gate material to form at least one gate electrode.
Other advantages and features of the present invention will become readily apparent to those skilled in this art from the following detailed description. The embodiments shown and described provide illustration of the best mode contemplated for carrying out the invention. The invention is capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings are to be regarded as illustrative in nature, and not as restrictive.